Previously, he had replaced the chip in an Atari cartridge with an EEPROM that he could reprogram via a ribbon cable. This new iteration places that EEPROM inside the case of the gaming console along with a PIC development board. The PIC board interfaces an SD card with somewhere around 1200 ROMs on it. Three switches added to the front of the Atari allow the user to cycle through available games and flash the desired title to the EEPROM. As you can see, a 2×16 LCD display now resides in the cartridge opening.

(The article and pictures websites listed above are in a language I don't understand, so I borrowed heavily from a Hack-A-Day article for the information in the post. I hope they don't mind.)